It is well known in the art to utilize conventional powered or hand operated fastener driving devices to drive a nail or staple into a substrate. However, when fastening frangible materials, such as felt, plastic house wrap, sheeting, roofing, tar paper or the like, it often is necessary to use a so-called fastener cap with the nail or staple. Such caps minimize damage to the sheet material from the fastener and reduce leakage of moisture at the location of the fastener.
Originally, such fastener caps were applied manually by holding the fastener down against the substrate before applying the nail or staple and then manually driving the nail or staple through the fastener and sheet material into the substrate or work surface.
Because of the desirability of the use of such fastener caps, and the labor intensive, and hence expensive, process of manually applying the caps to the work substrate or work piece, a number of different forms of cap feeding devices have been developed over the years for use with automatic air or electric powered fastener drivers and also others for use with manual fastener drivers. However, typically such cap feeding devices are bulky, heavy, hard to handle, and require substantial modification of the underlying fastener tool for operation. Examples of complex automatic cap feeders for use with powered fastening devices are shown in U.S. Pat. Nos. 6,145,725 and 5,934,504.
Cap feeding devices designed for use with manual fastener drivers and particularly the well-known Arrow T50 and HT50 brand staple gun tackers are shown in U.S. Pat. Nos. 3,385,498 and 6,966,389 respectively. These devices each require the replacement or modification of some portion of the original staple gun with a modified component. For example, in U.S. Pat. No. 3,385,498 a modified nose piece for the staple gun is required to be used, while in U.S. Pat. No. 6,966,389 the movable striker or driver 14 must be replaced with a striker or driver that has at least one perforated side wall to accept a pivotal connection, or that side wall must be modified to provide a pivot hole before the feed device can be attached.
Accordingly, there is a present need for a continuous cap feeder assembly that can be easily attached to an existing hand operated fastener driving device, e.g. a staple gun tacker, without the need for any modification of the fastener driving device by the owner. Such a feed mechanism can be sold and marketed separately from a conventional staple gun tacker for retro fitting and/or removable mounting from the tacker.
While the present invention described herein is being directed particularly to a well-known HT50 brand staple gun tacker, as would be understood by those skilled in the art it can be readily adapted to other types of fastener driving devices, such as staple gun tackers or nailers, whether hand operated or powered by compressed air or electricity. Accordingly, as used herein, the terms fastener driving device and fastener respectively include staple guns, staple gun tackers, nailers and staples and nails or the like.